<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta http-equiv="X-UA-Compatible" content="ie=edge">
  <title>Document</title>
  <!-- <link rel="stylesheet" href="https://cdn.bootcss.com/twitter-bootstrap/3.3.7/css/bootstrap.css"> -->
  <link rel="stylesheet" href="css/bootstrap.min.css">
  <style media="screen">
    div {
      width: 25%;
      float: left;
    }
  </style>
</head>
<body>


  <div class="col-md-2">
  <h3>主侧栏</h3>
    Use this document as a way to quickly start any new project.Use this document as a way to quickly start any new project.Use this document as a way to quickly start any new project.Use this document as a way to quickly start any new project.Use this document as a way to quickly start any new project.</div>
  <div class="col-md-8">
    <h3>内容</h3>
    Use this document as a way to quickly start any new project.Use this document as a way to quickly start any new project.Use this document as a way to quickly start any new project.Use this document as a way to quickly start any new project.Use this document as a way to quickly start any new project.</div>
  <div class="col-md-2">
    <h3>右侧栏</h3>
    Use this document as a way to quickly start any new project.Use this document as a way to quickly start any new project.Use this document as a way to quickly start any new project.Use this document as a way to quickly start any new project.Use this document as a way to quickly start any new project.</div>
</body>
</html>
